Shaped electrical conductor

ABSTRACT

A shaped electrical conductor ( 610, 630 ) includes a first sheet of metal ( 319 ) with a first and second thermoplastic adhesive pattern ( 311, 312 ). The second pattern is justified with the first pattern. The first sheet is etched to remove metal not covered by the thermoplastic adhesive patterns so that no metal bridges remain between disconnected coated portions. A second sheet of metal ( 339 ) has a third and fourth thermoplastic adhesive pattern ( 333, 334 ) on a second surface and the fourth pattern is justified with the third pattern. The second sheet is etched to remove metal not covered by the thermoplastic adhesive patterns so that no metal bridges remain between disconnected coated portions. First and second contact regions ( 315, 335 ) in the second and third adhesive patterns are in electrical contact.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly-assigned U.S. patent application Ser. No.13/445,114, filed Apr. 12, 2012, and granted as U.S. Pat. No. 8,623,226,entitled MAKING STACKED PANCAKE MOTORS USING PATTERNED ADHESIVES, bySchindler et al.; the disclosure of which is incorporated herein.

FIELD OF THE INVENTION

This invention relates to electric motors in general and in particularto electric motors having a flat armature wherein the armature comprisesa conductive pattern formed on an insulating substrate.

BACKGROUND OF THE INVENTION

Electric motors are used in a wide variety of applications. In many ofthese applications, the weight of the motor is of critical importance.For example, in an electric car the overall weight of the vehicle is animportant factor limiting the distance that the vehicle can be operatedgiven a fixed battery capacity. However, given current designs, theelectric motor itself can be among the heavier components in thevehicle. Thus while it is desirable to provide an electric motor have ahigh-power output for vehicle use, it is also desirable to have such amotor remain at a lower weight.

It will be appreciated that lighter weight electrical motors areotherwise desirable in many other applications as such motors and themanufactured goods in which such electric motors are incorporated aremore easily transported, carried, manipulated, and used. Further, costreductions and recycling advantages can be obtained where weightreductions are achieved by lighter weight electrical motors that requireless material.

However, conventional wound motor designs do not readily lend themselvesto weight reduction. One reason for this is that conventional wound coilmotor designs require an armature or a stator having coiled conductorsthereon. The coils are typically formed by winding wire on metalliclaminates. The laminates provide shaped features about which the coils,typically made from a metal such as copper, can be wound.

These laminates add significant mass to the motor. This mass affects theoperation of the system in which the motor is used by lowering thepower-to-weight ratio of the system. In some cases, eddy currents canarise in the laminates, further reducing motor efficiency and loweringpower-to-weight ratios.

In the case of an armature, the laminate mass can cause motorinefficiency in two additional ways. First, this laminate mass increasesthe inertia that must be overcome to start and stop rotation. Second,the laminate mass is at a distance from the axis of rotation of thearmature. In an armature that has a shaft that has any eccentricity, orthat has laminates that are not aligned with the shaft, this can createstatic and dynamic balance problems that consume energy. Additionally,shaft eccentricity and misaligned laminates affect the placement of thewindings on the laminates, so the effects of any shaft eccentricity orlaminate misalignment are further enhanced by the mass of the windings.

One effort to reduce the use of such laminates involves pancake or flatmotors. Conventional flat motors are used in a variety of applications.For example, U.S. Pat. No. 8,076,808 describes a flat vibration motor,such as can be used in a cellular telephone. EP 0548362A1 describesconstruction of a typical prior-art flat motor, also known as a “pancakemotor.” The example described is a flat coreless DC motor having flatarmature coils mounted on a disk. The coils are wound into sectors ofthe disk. The disk can be the rotor and can be mounted over a statorincluding a field magnet. When current is passed through the coils via acommutator, the rotor turns.

Various ways of manufacturing pancake motors, and specifically windingsand rotors for pancake motors, have been described. WO 2009/038648describes applying insulating material over a pre-formed electricalconductor and heating the assembly to activate an adhesive that bondsthe insulating material to the conductor. However, this requires aninsulator that includes the heat-activated adhesive, and requires thatthe conductors be formed to shape before being insulated.

U.S. Patent Publication No. 2002/0105237 describes a stator for a planarlinear motor. The stator includes magnetic sheets (i.e., sheets of amaterial that can complete a magnetic circuit) set vertically and boundtogether, e.g., using a fluid hardening material or an epoxy resin.

However, such pancake motors use laminate structures that extendtypically further from an axis of rotation than do conventional motors,creating increased balance problems, and adding weight. Further suchmotors have limited performance characteristics compared to conventionalwound laminate motors.

What is needed in the art are motors that provide conventionalperformance characteristics while offering reduced motor mass. What isalso needed in the art are new methods for motor manufacture.

SUMMARY OF THE INVENTION

Briefly, according to one aspect of the present invention a shapedelectrical conductor includes a first sheet of metal with a firstthermoplastic adhesive pattern on a first surface and a secondthermoplastic adhesive pattern on a second surface. The second patternis justified with the first pattern. The first sheet is etched to removemetal not covered by the thermoplastic adhesive patterns so that nometal bridges remain between disconnected coated portions of the firstsheet. A second sheet of metal has a third thermoplastic adhesivepattern on a first surface and a fourth thermoplastic adhesive patternon a second surface and the fourth pattern is justified with the thirdpattern. The second sheet is etched to remove metal not covered by thethermoplastic adhesive patterns so that no metal bridges remain betweendisconnected coated portions of the second sheet. First and secondcontact regions in the second and third adhesive patterns are bonded sothat the contact regions are in electrical contact.

The invention and its objects and advantages will become more apparentin the detailed description of the preferred embodiment presented below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational cross-section of an electrophotographicreproduction apparatus;

FIG. 2 shows various embodiments of methods of making a shapedelectrical conductor;

FIG. 3A is a top view of various examples of patterns;

FIG. 3B is a cross-section along the line 3B-3B in FIG. 3A;

FIG. 4 is a partial perspective view showing a pancake motor accordingto the prior art;

FIG. 5 is a cross-section of a pancake motor according to variousembodiments; and

FIG. 6 is a top view of magnets and thermoplastic adhesive patternsaccording to various embodiments.

The attached drawings are for purposes of illustration and are notnecessarily to scale.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 shows various embodiments of methods of making a shapedelectrical conductor. Processing begins with step 210 or step 250. Instep 210, a first sheet of metal having a first thickness is provided.The first sheet of metal, and other sheets of metal described herein,can be any electrically-conductive metal. For example, copper oraluminum can be used. Step 210 is followed by step 215 and step 220,which can be performed in any order.

In step 215, a first thermoplastic adhesive pattern is applied to afirst surface of the first sheet. The term “adhesive,” as used herein,does not require a pressure-sensitive adhesive, or one that is tackyunder normal environmental conditions. An adhesive has the capability ofadhering during bonding, described below with reference to step 290, butis not necessarily a glue, tape, cement, or epoxy (although it can beany of those in various embodiments). In various embodiments, step 215includes steps 217 and 225. Step 215 is followed by step 225.

In step 217, an electrophotographic print engine is used to depositthermoplastic particles in a corresponding deposition pattern.Electrophotography can also be used for steps 220, 255, and 260. Moredetail of electrophotographic deposition is given in FIG. 1, discussedbelow. The first plastic pattern can also be applied by flood-coating orspin-coating over a mask that defines the deposition pattern. Step 217is followed by step 218.

In step 218, the deposited particles are fixed to the correspondingsheet under heat or pressure. This is also described below withreference to FIG. 1, and can also be used in steps 220, 255, and 260.

In step 220, a second thermoplastic adhesive pattern is applied to asecond surface of the first sheet. The second pattern is fully justifiedwith the applied first pattern. “Fully justified” means that, withintolerances, the first and second thermoplastic adhesive patterns overlapcompletely as viewed along a normal to the first sheet. In variousembodiments, the first and second thermoplastic patterns aremirror-images of each other. As a result, within tolerances, at anypoint on the first sheet, a ray passing through the point along thenormal to the sheet at that point either passes through both the firstand second thermoplastic patterns, or through neither pattern. Step 220is followed by step 225.

In step 225, the first sheet is etched to remove metal not covered bythe thermoplastic adhesive patterns so that no metal bridges remainbetween disconnected coated portions of the first sheet. Since the metalis covered on both sides by the fully justified first and secondthermoplastic patterns, the sheet will be etched through where thepatterns are absent, and protected where the patterns are present. Someunder-cutting due to over-etching can occur at the edges of protectedareas. Step 225 is followed by step 290.

In step 250, a second sheet of metal having a second thickness isprovided. This is as described above with reference to step 210. Step250 is followed by step 255 and step 260.

In step 255, a third thermoplastic adhesive pattern is applied to afirst surface of the second sheet. This is as described above withreference to step 215. The third thermoplastic adhesive pattern can bethe same as, or different from, either the first or second thermoplasticadhesive patterns. Step 255 is followed by step 265.

In step 260, a fourth thermoplastic adhesive pattern is applied to asecond surface of the second sheet, the fourth pattern being fullyjustified with the applied third pattern (as above, step 220; same ordifferent, as in step 255). Step 260 is followed by step 265.

In step 265, the second sheet is etched to remove metal not covered bythe thermoplastic adhesive patterns so that no metal bridges remainbetween disconnected coated portions of the second sheet. This is asdiscussed above with reference to step 225. Step 265 is followed by step290.

The result of steps up to 290 is a pair of metal sheets carryingpatterned conductors. The first and second patterns can be the same as,or different from, the third and fourth patterns. The first and secondmetal sheets can be at least 0.1 mm thick. At least one of thethermoplastic adhesive patterns can include a plurality of traces (e.g.,lines, curves, or segments thereof), each having a trace width less than2 mm (e.g., 50 mil=1.25 mm). Spaces between traces can have space widthsless than 2 mm (e.g., 50 mil=1.25 mm). Traces and spaces can also be 2mm or wider.

In step 280, a first contact region in the second adhesive pattern isselected. In step 285, a second contact region in the third adhesivepattern is selected. Steps 280 and 285 can be performed in any order.The first and second contact regions are selected so that current willbe able to flow through the conductors. An example is shown in FIG. 3.Steps 280 and 285 are followed by step 290.

In step 290, the second and third adhesive patterns are bonded to eachother at more than one point. The sheets are brought together so thatthe second and third patterns can be bonded. No orientation of thesheets is implied by the designation of certain patterns as the secondand third. Step 290 is followed by step 295 and optional step 292.

In step 295, the first and second sheets are mated so that the firstcontact region is in electrical contact with the second contact region.Step 295 can be performed as described with reference to optional steps292 and 294. Step 295 is followed by optional step 297.

In optional step 292, the two sheets are heated and pressed together tobond them. This step can be used with toner-based thermoplastic patternsby heating the patterns above their glass transition temperatures T_(g).The patterns are then pressed together to squeeze toner out from betweenthe metal in the first and second contact regions, so that the metalareas in the two sheets come into electrical contact. The toner is thencooled below T_(g) to fix the sheets together. This type of bonding isdescribed below with respect to fuser 60 (FIG. 1) in the context offusing toner to a receiver. In other embodiments, conductive toner canbe used, or not all the toner squeezed out from between the sheets inthe contact areas. In other embodiments, toner can be removed from thefirst and second contact regions by softening the toner (temperature>T_(g)) with a heat source, then removing the toner with a skive,vacuum, blow-off gun, abrasion wheel, or other mechanical device adaptedto move or remove viscous toner. The heat source can be part of thedevice; for example, a heated skive can be used to simultaneously heatand move the toner. Step 292 is followed by step 295.

In optional step 294, the mating step includes applying a conductiveadhesive to the first or second contact region and bringing the twocontact regions into mechanical contact with the applied adhesive. Forexample, dimethyl, methylhydrogen siloxane, e.g., DOW CORNING 7920, canbe used. Silver-containing siloxane, e.g., DOW CORNING® DA 6524, canalso be used. Adhesives can include >80 wt % silver, or 90 wt % silver.Step 294 is followed by step 295.

In optional step 297, the mating step includes soldering or welding thefirst contact region and the second contact region together.

In various embodiments, steps corresponding to steps 210, 215, 220, 225are performed to apply fifth and sixth fully-registered thermoplasticpatterns on a third metal sheet having a third thickness. The thirdsheet is then etched. This is as described above. Contact areas areselected in the fourth and fifth thermoplastic layers, and the secondand third sheets are bonded and mated as described above (steps 290,295). This forms a three-metal-sheet structure. The thicknesses of themetal sheets can be the same as or different from each other.

In various embodiments, a third sheet of metal having a third thicknessis provided. A fifth thermoplastic adhesive pattern is applied to afirst surface of the third sheet, and a sixth thermoplastic adhesivepattern fully justified with the applied fifth pattern is applied to asecond surface of the third sheet. The third sheet is etched to removemetal not covered by the thermoplastic adhesive patterns so that nometal bridges remain between disconnected coated portions of the thirdsheet. This is as described above for the first and second sheets.

A third contact region is then selected in the fourth adhesive pattern,e.g., as described above for the first contact region. A fourth contactregion is selected in the fifth adhesive pattern, e.g., as describedabove for the second contact region. The fourth and fifth adhesivepatterns are bonded to each other at more than one point, resulting in astructure with three metal layers: the first and second metal layersbonded to each other, and the second and third metal layers bonded toeach other. The second and third sheets are then mated, as describedabove, so that the third contact region is in electrical contact withthe fourth contact region.

FIG. 3A is a top view of various examples of patterns. First pattern 311(and also the second, hidden in the top view since the patterns are inregister) is shown solid; third pattern 333 (and the fourth pattern) isshown dashed. The edges of the patterns are shown; for example, thedashed shape of third pattern 333 encloses the area in the pattern wherethermoplastic and metal are intended to be. In the example shown here,the first and second patterns are circular and the third and fourthpatterns are elliptical spirals. The long axis of the elliptical spirals(e.g., third pattern 333) is twice a length of an axis of the first andsecond circular patterns (first pattern 311).

First contact region 315 in second adhesive pattern (hidden under firstadhesive pattern 311) is a small disk. Second contact region 335 inthird pattern 333 is a slightly larger disk. The two contact regions315, 335 overlay, forming electrical contact between the metal protectedfrom etching in regions 315, 335. As a result, current into electrode360 defined by third pattern 333 travels through the spiral conductordefined by third pattern 333, the conductor defined by second contactregion 335, the conductor defined by first contact region 315, electrode370 defined by first pattern 311, the circle defined by first pattern311, and out electrode 380 defined by first pattern 311.

Corners in the patterns can be chamfered or not. The width of thepattern can vary or not at various points on the pattern; the exampleshown does not vary the width of the pattern at corners.

FIG. 3B is a cross-section along the line 3B-3B in FIG. 3A. Firstconductor 610 is defined by first pattern 311 and second pattern 312. Inthis section, two segments of conductor 610 are visible. Secondconductor 630 is defined by third pattern 333 and fourth pattern 334.Conductor 630 is shown below conductor 610, but can be above it. In thissection, twelve segments of conductor 630 are visible. First conductor610 and second conductor 630 are, respectively, the etched first andsecond metal sheets 319, 339. First contact region 315 and secondcontact region 335 are shown electrically connected by conductiveadhesive 355 to carry current between them. In the embodiment shown,toner has been removed from first contact region 315 and second contactregion 335 prior to applying conductive adhesive 355, as discussedabove.

First pattern 311 is formed in first metal sheet 319. For clarity, metalsheet 319 is labeled on only one of the visible conductor segments.However, as shown in FIG. 3A, all of the visible conductor segmentscorresponding to first pattern 311 are part of metal sheet 319.Likewise, second pattern 312 is formed on second metal sheet 339. Thesides of the segments of first metal sheet 319 and second metal sheet339 are shown undercut to represent graphically the possibility ofover-etching of the metal sheet. No particular cross-sectional shape ofthe conductor segments is required.

First metal sheet 319 has first thermoplastic pattern 311 on its topsurface and second thermoplastic pattern 312 on its bottom surface.Second metal sheet 339 has third thermoplastic pattern 333 on its topsurface and fourth thermoplastic pattern 334 on its bottom surface. Forclarity, only one segment is labeled, even though the thermoplasticpatterns are continuous within a layer, as shown in FIG. 3A. As shown,second thermoplastic pattern 312 and third thermoplastic pattern 333have been pressed together to bond first metal sheet 319 to second metalsheet 339.

In various embodiments of the use of this structure as a motor winding,fluid is passed through the winding as indicated by the “FLUID FLOW”arrow. The fluid can be ethylene glycol, deionized water, air, nitrogen,or another fluid adapted to remove Joule heat from the conductors inmetal sheets 319, 339. Fluid can be pumped or otherwise moved actively,or permitted to flow passively by convection.

Referring to FIGS. 3A and 3B, bonding area 390 (shown hatched withhorizontal lines) is an area in which the second and third patternsoverlap. Consequently, when first metal sheet 319 and second metal sheet339 are bonded together, the thermoplastic adhesive of second pattern312 and of third pattern 333 in bonding area 390 adhere to each other.This adhesion of metal sheets 319, 339 to each other provides mechanicalstrength to the resulting assembly. In various embodiments, a pluralityof the regions of overlap between second pattern 312 and third pattern333, or all of the overlap regions, are bonding regions. FIGS. 3A and 3Bshow several bonding regions hatched with horizontal lines. Otherbonding regions besides those shown hatched can be used.

In various embodiments described above in which three sheets of metalare used, the fifth thermoplastic pattern (not shown) is a rotation offirst thermoplastic pattern 311. That is, respective rotation centers ofthe first and fifth thermoplastic patterns are aligned and the fifththermoplastic pattern is rotated about its rotation center with respectto first thermoplastic pattern 311. Other than the rotation, the fifththermoplastic pattern is identical to first thermoplastic pattern 311(within manufacturing tolerances). Since the fifth and sixththermoplastic patterns are fully justified, the sixth thermoplasticpattern is also a rotation of second thermoplastic pattern 312.

As is shown here, the motor so formed does not have a laminate portionand therefore can have reduced mass and density as compared to the priorart. Moreover, in embodiments in which no laminate or other core isused, there are no losses due to in-core eddy currents.

FIG. 4 is a partial perspective view showing a pancake motor accordingto the prior art. The pancake motor is brushless motor having housingwith upper housing 410 and lower housing 412. Printed circuit board(PCB) 420 is installed in upper housing 410. Stator 430 is disposed overunderside 429 of PCB 420. Stator 430 includes a plurality of coil layerspiled up on top of each other, e.g., by photolithography. Rotor 440 isspaced apart from the lower surface of stator 430 and includes permanentmagnets 442 disposed at an inner peripheral surface of rotor 440. Thepermanent magnets have opposite orientations as they are around therotor, as shown (alternating N and S poles facing down). Rotating shaft460 is rotatably connected to upper housing 410 by a bearing in opening415, and an electric signal control unit 470 installed at an end portionof the PCB 420 and periodically supplying electric current to stator430.

PCB 420 includes an annular base 421 and an elongated plate 423integrally formed at an end portion of annular base 421. Elongated plate423 extends out of upper housing 410 through opening 418 formed at aside wall of upper housing 410.

Stator 430 can be formed over underside 429 of PCB 420 byphotolithography. In various embodiments, a conductive material such ascopper is applied on underside 429 of PCB 420 to form a copper layer. Aphoto-active solution is deposited over the copper, and a photo mask onwhich the coil shape is printed is placed on the solution.

When the photo mask is irradiated, a coil shape that is similar to thephoto mask is patterned on the surface of the solution on the copperlayer. After exposure, an etching solution is applied to PCB 420. Theetching solution reacts with the photoactive layer and copper layer sothat a first coil layer is formed, i.e., by removing undesired copper.After forming the first coil layer, a first insulation layer is formedon the underside of the first coil layer. Multiple conductive layers canbe formed in this way, and vias can be drilled and plated between themto connect them.

Rotor 440 is spaced apart from the underside of stator 430 by thepredetermined distance. Rotor 440 has a cylindrical shape, and haspermanent magnets 442 which are radially disposed on an upper surface ofrotor 440 in such a manner that adjacent permanent magnets 442 havedifferent poles from each other to generate a magnetic field which makeselectromagnetic-interaction with the electric field of stator 430 torotate rotor 440, rotating shaft 460 is integrally formed at a center ofrotor 440, so as to rotate when rotor 440 rotates.

Upper housing 410 is formed at an upper portion thereof with a circularopening 415, and an upper and lower bearings 452 and 454 are mounted atan inner portion of upper housing 410. Accordingly, rotating shaft 460is rotatably attached to upper housing 410 by upper and lower bearings452 and 454.

Upper housing 410 includes bracket 413 formed on the bottom edgethereof, including hole 411. Lower housing 412 includes bracket 414formed on the top edge thereof, including hole 481. A fixing member 416such as a bolt penetrates holes 411 and 481 so that upper and lowerhousings 410 and 412 are integrally assembled. Other assembly techniquescan also be used. Multiple brackets per housing can also be used, asshown here.

Further details of pancake motors are given in U.S. Pat. Nos. 6,005,324;7,112,910; 7,608,964; and 7,573,173, the disclosures of which areincorporated herein by reference.

FIG. 5 is a cross-section of a pancake motor according to variousembodiments. This section is taken along the line 5-5 in FIG. 6.

There are two commonly-used types of configurations of pancake motorwindings. In a first configuration type, wires are arranged to extendsubstantially radially on rotor 515, and to be substantially straightwhere they pass magnets 442D, 442E. The Lorentz force on the chargecarriers in the conductors is tangential, in accordance with Fleming'sleft-hand rule for motors. In some of these configurations, individualwires extend radially out rotor 515, past one magnet (e.g., magnet442D), then radially back in past a different magnet (e.g., magnet442E). In other configurations, squared-off spiral windings in the planeof rotor 515 are used, and the tangential portions of those spirals arearranged beyond magnets 442D, 442E so they do not contribute significantradial Lorentz forces. The sections of the spirals that pass the magnetscontribute tangential forces.

In a second type of configurations, the wires are formed into tight,approximately circular spirals. These coils act as solenoids and producedistinct north and south magnetic poles when current is passed throughthem. These poles attract and repel the poles of magnets 442D, 442E,providing tangential forces.

In this example, rotor 515 is mounted on bearings 518. Shaft 510 isconnected to the center of rotor 515 to transmit rotary motion. Magnets442D, 442E, which can be permanent magnets or electromagnets, areattached on one face of rotor 515. Any number of magnets can be used,arranged in a circle around the face of rotor 515, as shown by magnets442 (FIG. 4). Rotor 515 can also include optional bracket supportingoptional magnets 521. Arrows indicate the direction of the magneticfield between magnets 442D, 442E, and 521. Other configurations can beused, such as magnets only over or only under the stator, magnets aroundthe stator, or combinations of these. The shaft can pass through anopening in the stator, and can be attached to the top or bottom of therotor.

Stator 550 is arranged opposite magnets 442D, 442E, or between those andmagnets 521. Stator 550 includes first conductor 610 defined by firstand second thermoplastic patterns 311, 312 (FIG. 3B). Stator 550 alsoincludes second conductor 630 defined by third and fourth thermoplasticpatterns 333, 334 (FIG. 3B). In this section, two segments of eachconductor 610, 630 are visible. The direction of current flow in eachsegment is shown by vector symbols. As shown, the direction of force oneach conductor segment F is to the right according to the left-hand rule(pointer finger for magnetic field direction, middle finger for currentdirection; thumb for resultant force on the conductor). Since the statoris fixed, the equal and opposite force turns the rotor, as shown in FIG.6.

FIG. 6 is a top view of magnets and first and third thermoplasticadhesive patterns according to various embodiments, includingembodiments useful in the motor shown in FIG. 5. As in FIG. 3A, thesecond and fourth thermoplastic patterns are not visible. For clarity,only the centerline of the conductors in each pattern is shown; thepatterns are broader than the indicated centerlines. First pattern 311is shown solid and third pattern 333 is shown dashed. First pattern 311defines first conductor 610; third pattern 333 defines second conductor630, which is formed from the second metal sheet. The configuration ofconductors 610, 630 and AC supply 609 shown here is a stator; rotors canalso be formed as described above with reference to FIG. 2. Wherepatterns 311, 333 overlap, e.g., at bonding area 390, conductors 610,630 are bonded together for mechanical support. In various embodiments,a rotor for a brushless motor is formed. Rotors or stators can have twoor any higher number of layers.

For clarity, conductors 610 and 630 are shown passing only once aroundthe stator. Each conductor can have any number of nested turns with thesame pattern, but progressively smaller. Conductors 610, 630 arearranged so that the force provides rotational motion, as describedbelow.

Current is provided to the stator by AC supply 609. In FIG. 6, currentflow is shown at a point in time at which the supply is providingcurrent into second conductor 630. Conductors 610, 630 are electricallyconnected in respective contact areas 315, 335, as discussed above withreference to FIGS. 3A and 3B. Current flows from the positive terminalof AC supply 609 through second conductor 630, contact area 335, contactarea 315, and conductor 610, then to the negative terminal of AC supply609.

This stator can be used with an eight-pole rotor including magnets 442A,442B, 442C, 442D, 442E, 442F, 442G, and 442H. The magnets can be over orunder the stator, e.g., as shown in FIG. 5. Arrows on conductors 610,630 represent the direction of current I in those conductors, and arrowsorthogonal to conductors 610, 630 represent the direction of force F.The direction of the magnetic field from each magnet is shown bystandard vector symbols (dots and crosses). Magnets 442A, 442C, 442E,and 442G have the magnetic field (N-S) into the plane of the drawing.Magnets 442B, 442D, 442F, and 442H have the magnetic field (N-S) out ofthe plane of the drawing.

Where conductor 630 passes magnet 442A (i.e., crosses over or under, orpasses near or adjacent to, magnet 442A), the direction of current flowis in towards the center of the stator, as shown. The magnetic field isinto the page. The resulting force on the stator is clockwise, as shown.Since the stator is fixed, the equal and opposite reaction will drivethe rotor counter-clockwise. Conductor 610 is arranged so that thecurrent through conductor 610 where it passes magnet 442A is alsotowards the center of the stator, so the force on the stator is alsoclockwise, as shown. Current is also inward, and force on the statorclockwise, where conductors 610, 630 pass magnets 442C, 442E, and 442G.

In this example, the forces from conductors 610, 630 where they passmagnet 442A are not entirely tangential. This is because conductors 610,630 are not entirely radial where they pass magnet 442A. Conductors canbe entirely radial or not, as long as the tangential components of theforces from the magnets sum to provide torque in a particular direction.Tangential arcs 619, 639 are shown for comparison between the directionsof the force vectors and the tangential directions.

Where conductors 610, 630 pass magnet 442D (and also magnets 442B, 442F,and 442H), current flow is away from the center of the stator. Magneticfield is directed out of the page. Since the directions of current flowand magnetic field are both reversed from the situation over magnet442A, the force on the stator is still clockwise, so the rotor is drivencounterclockwise.

When the rotor rotates so that magnet 442B is passing the statorconductors that formerly passed magnet 442A, AC supply 609 reversespolarity. Current is provided into conductor 610 and out of conductor630, so that the direction of force continues to be clockwise and thedirection of rotation counterclockwise.

In embodiments in which conductors 610, 630 form a rotor, the conductorsare driven clockwise. In these embodiments, brushes can be used totransmit current between AC supply 609 and conductors 610, 630. Innormal operation, the polarity of AC supply 609 reverses once permagnet, so current over magnet 442A is directed inward in the positionshown, and also inward after ⅛ revolution of the rotor together with apolarity change of AC supply 609. To change the direction of rotation ofthe motor, the polarity of AC supply 609 over each magnet is reversed.That is, in the position shown in FIG. 6, current over magnet 442A isdirected outward rather than inward.

As shown, contact regions 315, 335 are not centered in the stator. Theycan be centered (e.g. as shown in FIG. 3A) or not. In embodiments inwhich conductors 610, 630 are used as a rotor, an axle can be attachedat center of rotation 628. In various embodiments, particularly rotorembodiments, it is desirable to mechanically balance conductors 610, 630to reduce lateral forces acting at center of rotation 628. Static ordynamic balance, or both, can be desirable.

In various embodiments, first pattern 311, third pattern 333, or both,along with corresponding second or fourth patterns, include balancingfeatures that give the rotor uniform centrifugal force as it rotatespast a selected observation point. Specifically, the first and secondpatterns, or the third and fourth patterns, define or include balancingfeatures in the metal not removed from the corresponding metal sheet bythe corresponding etching step. The balancing features can be located inareas of the patterns 311, 333 that do not pass any magnets (e.g.,442A).

In this example, balancing feature 615 is an area of conductor 610 ofthe same mass as contact area 315, disposed diametrically oppositecontact area 315 with respect to center of rotation 628. Consequently,while conductors 610, 630 rotate, contact area 315 and balancing feature615 exert on the axis of rotation centrifugal forces equal in magnitudebut opposite in direction. These forces cancel out to maintain balance.Likewise, balancing features 635A, 635B together exert a centrifugalforce cancelling out that of contact area 335. A balancing feature caninclude one or more areas of additional mass, or one or more areas ofreduced mass. Mass can be reduced, e.g., by thinning the conductors.Balancing features can also include extra mass along the length ofconductors 610 or 630 except for certain areas. In this way, mass caneffectively be reduced to balance, but without reducing thecurrent-carrying capacity of the conductors.

In another example, one or more balancing features 616 can be frangible.A frangible balancing feature can be separated from the conductor 610,630 of which it is part. This separation can be performed aftermanufacture of a complete motor, or after bonding step 290 or matingstep 295 (FIG. 2). Separation can provide balance adjustments to improvedynamic or static balance. Frangible balancing feature 616 can beconnected to a conductor 610, 630 with a perforated pattern or narrowneck that can be fractured, or with metal that is stamped or punchedthinner than the rest of the metal sheet 319, 339 (FIG. 3B). In variousembodiments, the metal sheet (e.g., sheet 319 or 339) corresponding tofrangible balancing feature 616 can be stamped or punched to definebreak line 617 (e.g., of thinner or perforated metal) along whichfrangible balancing feature 616 can be separated from the correspondingmetal sheet 319, 339. In the example shown here, feature 616 is attachedto conductor 610 at a bend thereof, along two perforated break lines 617(for clarity, only one is shown).

Referring to FIG. 6 and also to FIGS. 3A-3B, in other embodimentsforming a rotor using conductors 610, 630, one or more of the conductors610, 630 is deliberately unbalanced. For example, first pattern 311 andsecond pattern 312 can define optional unbalanced feature 657. Feature657 is an area of metal not etched from first metal sheet 319 that isnot balanced by a corresponding feature opposite center of rotation 628from feature 657. As a result, when the rotor spins, it will vibrate.This can be used for non-audio indication, e.g., in a cellulartelephone. Feature 657 can be positioned and sized to produce a desiredvibration. More than one unbalanced feature can be included.Specifically, first and second patterns 311, 312, or third and fourthpatterns 333, 334, can define an unbalanced feature 657 in the metal notremoved from the corresponding metal sheet 319, 339 by the correspondingetching step.

The electrophotographic (EP) printing process can be embodied in devicesincluding printers, copiers, scanners, and facsimiles, and analog ordigital devices, all of which are referred to herein as “printers.”Electrostatographic printers such as electrophotographic printers thatemploy toner developed on an electrophotographic receiver can be used,as can ionographic printers and copiers that do not rely upon anelectrophotographic receiver. Electrophotography and ionography aretypes of electrostatography (printing using electrostatic fields), whichis a subset of electrography (printing using electric fields).

A digital reproduction printing system (“printer”) typically includes adigital front-end processor (DFE), a print engine (also referred to inthe art as a “marking engine”) for applying toner to the receiver, andone or more post-printing finishing system(s) (e.g. a UV coating system,a glosser system, or a laminator system). A printer can reproducepleasing black-and-white or color onto a receiver. A printer can alsoproduce selected patterns of toner on a receiver, which patterns (e.g.surface textures) do not correspond directly to a visible image. The DFEreceives input electronic files (such as Postscript command files)composed of images from other input devices (e.g., a scanner, a digitalcamera). The DFE can include various function processors, e.g. a rasterimage processor (RIP), image positioning processor, image manipulationprocessor, color processor, or image storage processor. The DFErasterizes input electronic files into image bitmaps for the printengine to print. In some embodiments, the DFE permits a human operatorto set up parameters such as layout, font, color, media type, orpost-finishing options. The print engine takes the rasterized imagebitmap from the DFE and renders the bitmap into a form that can controlthe printing process from the exposure device to transferring the printimage onto the receiver. The finishing system applies features such asprotection, glossing, or binding to the prints. The finishing system canbe implemented as an integral component of a printer, or as a separatemachine through which prints are fed after they are printed.

The printer can also include a color management system which capturesthe characteristics of the image printing process implemented in theprint engine (e.g. the electrophotographic process) to provide known,consistent color reproduction characteristics. The color managementsystem can also provide known color reproduction for different inputs(e.g. digital camera images or film images).

In an embodiment of an electrophotographic modular printing machine,e.g. the NEXPRESS 3000SE printer manufactured by Eastman Kodak Companyof Rochester, N.Y., color-toner print images are made in a plurality ofcolor imaging modules arranged in tandem, and the print images aresuccessively electrostatically transferred to a receiver adhered to atransport web moving through the modules. Colored toners includecolorants, e.g. dyes or pigments, which absorb specific wavelengths ofvisible light. Commercial machines of this type typically employintermediate transfer members in the respective modules for transferringvisible images from the photoreceptor and transferring print images tothe receiver. In other electrophotographic printers, each visible imageis directly transferred to a receiver to form the corresponding printimage.

Electrophotographic printers having the capability to also deposit cleartoner using an additional imaging module are also known. As used herein,clear toner is considered to be a color of toner, as are C, M, Y, K, andLk, but the term “colored toner” excludes clear toners. The provision ofa clear-toner overcoat to a color print is desirable for providingprotection of the print from fingerprints and reducing certain visualartifacts. Clear toner uses particles that are similar to the tonerparticles of the color development stations but without colored material(e.g. dye or pigment) incorporated into the toner particles. However, aclear-toner overcoat can add cost and reduce color gamut of the print;thus, it is desirable to provide for operator/user selection todetermine whether or not a clear-toner overcoat will be applied to theentire print. A uniform layer of clear toner can be provided. A layerthat varies inversely according to heights of the toner stacks can alsobe used to establish level toner stack heights. The respective tonersare deposited one upon the other at respective locations on the receiverand the height of a respective toner stack is the sum of the tonerheights of each respective color. Uniform stack height provides theprint with a more even or uniform gloss.

FIG. 1 is an elevational cross-section showing portions of a typicalelectrophotographic printer 100. Printer 100 is adapted to produce printimages, such as single-color (monochrome), CMYK, or hexachrome(six-color) images, on a receiver (multicolor images are also known as“multi-component” images). Images can include text, graphics, photos,and other types of visual content. An embodiment involves printing usingan electrophotographic print engine having six sets of single-colorimage-producing or -printing stations or modules arranged in tandem, butmore or fewer than six colors can be combined to form a print image on agiven receiver. Other electrophotographic writers or printer apparatuscan also be included. Various components of printer 100 are shown asrollers; other configurations are also possible, including belts.

Referring to FIG. 1, printer 100 is an electrophotographic printingapparatus having a number of tandemly-arranged electrophotographicimage-forming printing modules 31, 32, 33, 34, 35, 36, also known aselectrophotographic imaging subsystems. Each printing module 31, 32, 33,34, 35, 36 produces a single-color toner image for transfer using arespective transfer subsystem 50 (for clarity, only one is labeled) to areceiver 42 successively moved through the modules. Receiver 42 istransported from supply unit 40, which can include active feedingsubsystems as known in the art, into printer 100. In variousembodiments, the visible image can be transferred directly from animaging roller to a receiver 42, or from an imaging roller to one ormore transfer roller(s) or belt(s) in sequence in transfer subsystem 50,and then to receiver 42. Receiver 42 is, for example, a selected sectionof a web of, or a cut sheet of, planar media such as paper ortransparency film.

Each printing module 31, 32, 33, 34, 35, 36 includes various components.For clarity, these are only shown in printing module 32. Aroundphotoreceptor 25 are arranged, ordered by the direction of rotation ofphotoreceptor 25, charger 21, exposure subsystem 22, and toning station23.

In the EP process, an electrostatic latent image is formed onphotoreceptor 25 by uniformly charging photoreceptor 25 and thendischarging selected areas of the uniform charge to yield anelectrostatic charge pattern corresponding to the desired image (a“latent image”). Charger 21 produces a uniform electrostatic charge onphotoreceptor 25 or its surface. Exposure subsystem 22 selectivelyimage-wise discharges photoreceptor 25 to produce a latent image.Exposure subsystem 22 can include a laser and raster optical scanner(ROS), one or more LEDs, or a linear LED array.

After the latent image is formed, charged toner particles are broughtinto the vicinity of photoreceptor 25 by toning station 23 and areattracted to the latent image to develop the latent image into a visibleimage. Note that the visible image may not be visible to the naked eyedepending on the composition of the toner particles (e.g. clear toner).Toning station 23 can also be referred to as a development station.Toner can be applied to either the charged or discharged parts of thelatent image.

After the latent image is developed into a visible image onphotoreceptor 25, a suitable receiver 42 is brought into juxtapositionwith the visible image. In transfer subsystem 50, a suitable electricfield is applied to transfer the toner particles of the visible image toreceiver 42 to form the desired print image 38 on the receiver, as shownon receiver 42A. The imaging process is typically repeated many timeswith reusable photoreceptors 25.

Receiver 42A is then removed from its operative association withphotoreceptor 25 and subjected to heat or pressure to permanently fix(“fuse”) print image 38 to receiver 42A. Plural print images, e.g. ofseparations of different colors, are overlaid on one receiver beforefusing to form a multi-color print image 38 on receiver 42A.

Each receiver 42, during a single pass through the six printing modules31, 32, 33, 34, 35, 36, can have transferred in registration thereto upto six single-color toner images to form a pentachrome image. As usedherein, the term “hexachrome” implies that in a print image,combinations of various of the six colors are combined to form othercolors on receiver 42 at various locations on receiver 42. That is, eachof the six colors of toner can be combined with toner of one or more ofthe other colors at a particular location on receiver 42 to form a colordifferent than the colors of the toners combined at that location. In anembodiment, printing module 31 forms black (K) print images, 32 formsyellow (Y) print images, 33 forms magenta (M) print images, 34 formscyan (C) print images, 35 forms light-black (Lk) images, and 36 formsclear images.

In various embodiments, printing module 36 forms print image 38 using aclear toner or tinted toner. Tinted toners absorb less light than theytransmit, but do contain pigments or dyes that move the hue of lightpassing through them towards the hue of the tint. For example, ablue-tinted toner coated on white paper will cause the white paper toappear light blue when viewed under white light, and will cause yellowsprinted under the blue-tinted toner to appear slightly greenish underwhite light.

Receiver 42A is shown after passing through printing module 36. Printimage 38 on receiver 42A includes unfused toner particles.

Subsequent to transfer of the respective print images 38, overlaid inregistration, one from each of the respective printing modules 31, 32,33, 34, 35, 36, receiver 42A is advanced to a fuser 60, i.e. a fusing orfixing assembly, to fuse print image 38 to receiver 42A. Transport web81 transports the print-image-carrying receivers (e.g., 42A) to fuser60, which fixes the toner particles to the respective receivers 42A bythe application of heat and pressure. The receivers 42A are seriallyde-tacked from transport web 81 to permit them to feed cleanly intofuser 60. Transport web 81 is then reconditioned for reuse at cleaningstation 86 by cleaning and neutralizing the charges on the opposedsurfaces of the transport web 81. A mechanical cleaning station (notshown) for scraping or vacuuming toner off transport web 81 can also beused independently or with cleaning station 86. The mechanical cleaningstation can be disposed along transport web 81 before or after cleaningstation 86 in the direction of rotation of transport web 81.

Fuser 60 includes a heated fusing roller 62 and an opposing pressureroller 64 that form a fusing nip 66 therebetween. In an embodiment,fuser 60 also includes a release fluid application substation 68 thatapplies release fluid, e.g. silicone oil, to fusing roller 62.Alternatively, wax-containing toner can be used without applying releasefluid to fusing roller 62. Other embodiments of fusers, both contact andnon-contact, can be employed. For example, solvent fixing uses solventsto soften the toner particles so they bond with the receiver 42.Photoflash fusing uses short bursts of high-frequency electromagneticradiation (e.g. ultraviolet light) to melt the toner. Radiant fixinguses lower-frequency electromagnetic radiation (e.g. infrared light) tomore slowly melt the toner. Microwave fixing uses electromagneticradiation in the microwave range to heat the receivers (primarily),thereby causing the toner particles to melt by heat conduction, so thatthe toner is fixed to the receiver 42.

The receivers (e.g., receiver 42B) carrying the fused image (e.g., fusedimage 39) are transported in a series from the fuser 60 along a patheither to a remote output tray 69, or back to printing modules 31, 32,33, 34, 35, 36 to create an image on the backside of the receiver (e.g.,receiver 42B), i.e. to form a duplex print. Receivers (e.g., receiver42B) can also be transported to any suitable output accessory. Forexample, an auxiliary fuser or glossing assembly can provide aclear-toner overcoat. Printer 100 can also include multiple fusers 60 tosupport applications such as overprinting, as known in the art.

In various embodiments, between fuser 60 and output tray 69, receiver42B passes through finisher 70. Finisher 70 performs variousmedia-handling operations, such as folding, stapling, saddle-stitching,collating, and binding.

Printer 100 includes main printer apparatus logic and control unit (LCU)99, which receives input signals from the various sensors associatedwith printer 100 and sends control signals to the components of printer100. LCU 99 can include a microprocessor incorporating suitable look-uptables and control software executable by the LCU 99. It can alsoinclude a field-programmable gate array (FPGA), programmable logicdevice (PLD), microcontroller, or other digital control system. LCU 99can include memory for storing control software and data. Sensorsassociated with the fusing assembly provide appropriate signals to theLCU 99. In response to the sensors, the LCU 99 issues command andcontrol signals that adjust the heat or pressure within fusing nip 66and other operating parameters of fuser 60 for receivers. This permitsprinter 100 to print on receivers of various thicknesses and surfacefinishes, such as glossy or matte.

Image data for writing by printer 100 can be processed by a raster imageprocessor (RIP; not shown), which can include a color separation screengenerator or generators. The output of the RIP can be stored in frame orline buffers for transmission of the color separation print data to eachof respective LED writers, e.g. for black (K), yellow (Y), magenta (M),cyan (C), and red (R), respectively. The RIP or color separation screengenerator can be a part of printer 100 or remote therefrom. Image dataprocessed by the RIP can be obtained from a color document scanner or adigital camera or produced by a computer or from a memory or networkwhich typically includes image data representing a continuous image thatneeds to be reprocessed into halftone image data in order to beadequately represented by the printer. The RIP can perform imageprocessing processes, e.g. color correction, in order to obtain thedesired color print. Color image data is separated into the respectivecolors and converted by the RIP to halftone dot image data in therespective color using matrices, which comprise desired screen angles(measured counterclockwise from rightward, the +X direction) and screenrulings. The RIP can be a suitably-programmed computer or logic deviceand is adapted to employ stored or computed matrices and templates forprocessing separated color image data into rendered image data in theform of halftone information suitable for printing. These matrices caninclude a screen pattern memory (SPM).

Various parameters of the components of a printing module (e.g.,printing module 31) can be selected to control the operation of printer100. In an embodiment, charger 21 is a corona charger including a gridbetween the corona wires (not shown) and photoreceptor 25. Voltagesource 21 a applies a voltage to the grid to control charging ofphotoreceptor 25. In an embodiment, a voltage bias is applied to toningstation 23 by voltage source 23 a to control the electric field, andthus the rate of toner transfer, from toning station 23 to photoreceptor25. In an embodiment, a voltage is applied to a conductive base layer ofphotoreceptor 25 by voltage source 25 a before development, that is,before toner is applied to photoreceptor 25 by toning station 23. Theapplied voltage can be zero; the base layer can be grounded. This alsoprovides control over the rate of toner deposition during development.In an embodiment, the exposure applied by exposure subsystem 22 tophotoreceptor 25 is controlled by LCU 99 to produce a latent imagecorresponding to the desired print image. All of these parameters can bechanged, as described below.

Further details regarding printer 100 are provided in U.S. Pat. No.6,608,641 and in U.S. Publication No. 2006/0133870, the disclosures ofwhich are incorporated herein by reference.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the scope of theinvention.

PARTS LIST

-   21 charger-   21 a voltage source-   22 exposure subsystem-   23 toning station-   23 a voltage source-   25 photoreceptor-   25 a voltage source-   31 printing module-   32 printing module-   33 printing module-   34 printing module-   35 printing module-   36 printing module-   38 print image-   39 fused image-   40 supply unit-   42 receiver-   42A receiver-   42B receiver-   50 transfer subsystem-   60 fuser-   62 fusing roller-   64 pressure roller-   66 fusing nip-   68 release fluid application substation-   69 output tray-   70 finisher-   81 transport web-   86 cleaning station-   99 logic and control unit (LCU)-   100 printer-   210 provide first metal sheet step-   215 apply first plastic pattern step-   217 deposit electrophotographically step-   218 fix deposited particles step-   220 apply second plastic pattern step-   225 etch first sheet step-   250 provide second metal sheet step-   255 apply third plastic pattern step-   260 apply fourth plastic pattern step-   265 etch second sheet step-   280 select first contact region step-   285 select second contact region step-   290 bond patterns step-   292 heat and press sheets step-   294 apply adhesive step-   295 mate sheets step-   297 solder or weld step-   311 pattern-   312 pattern-   315 contact region-   319 metal sheet-   333 pattern-   334 pattern-   335 contact region-   339 metal sheet-   355 conductive adhesive-   360 electrode-   370 electrode-   380 electrode-   390 bonding area-   410 upper housing-   411 hole-   412 lower housing-   413 bracket-   414 bracket-   415 opening-   416 fixing member-   418 opening-   420 printed-circuit board (PCB)-   421 base-   423 plate-   429 underside-   430 stator-   440 rotor-   442 magnet-   442A magnet-   442B magnet-   442C magnet-   442D magnet-   442E magnet-   442F magnet-   442G magnet-   442H magnet-   452 bearing-   454 bearing-   460 rotating shaft-   470 control unit-   481 hole-   510 shaft-   515 rotor-   518 bearing-   521 magnet-   550 stator-   609 AC supply-   610 conductor-   615 balancing feature-   616 frangible balancing feature-   617 break line-   619 tangential arc-   628 center of rotation-   630 conductor-   635A balancing feature-   635B balancing feature-   639 tangential arc-   657 unbalanced feature-   I current-   F force

The invention claimed is:
 1. A shaped electrical conductor comprising: a first sheet of metal having a first thickness; a first thermoplastic adhesive pattern on a first surface of the first sheet; a second thermoplastic adhesive pattern on a second surface of the first sheet, the second pattern being fully justified with the applied first pattern; wherein the first sheet is etched to remove metal not covered by the thermoplastic adhesive patterns so that no metal bridges remain between disconnected coated portions of the first sheet; a second sheet of metal having a second thickness; a third thermoplastic adhesive pattern on a first surface of the second sheet; a fourth thermoplastic adhesive pattern on a second surface of the second sheet, the fourth pattern being fully justified with the applied third pattern; wherein the second sheet is etched to remove metal not covered by the thermoplastic adhesive patterns so that no metal bridges remain between disconnected coated portions of the second sheet; a first contact region in the second adhesive pattern bonded to a second contact region in the third adhesive pattern; and wherein the first and second sheets are mated so that the first contact region is in electrical contact with the second contact region.
 2. The shaped electrical conductor of claim 1 wherein the first and second patterns are different from the third and fourth patterns.
 3. The shaped electrical conductor of claim 1 wherein the first and second patterns are circular and the third and fourth patterns are elliptical spirals.
 4. The shaped electrical conductor of claim 3 wherein a long axis of the elliptical spirals is twice a length of an axis of the first and second circular patterns.
 5. The shaped electrical conductor of claim 1, wherein the first and second metal sheets are at least 0.1 mm thick.
 6. The shaped electrical conductor of claim 1, wherein one of the thermoplastic adhesive patterns includes a plurality of traces having widths less than 2 mm.
 7. The shaped electrical conductor of claim 1, wherein the two sheets are bonded by heating and pressing them together.
 8. The shaped electrical conductor of claim 1, wherein thermoplastic adhesive patterns are applied with an electrophotographic print engine.
 9. The shaped electrical conductor of claim 1, wherein the contact regions are soldered or welded together.
 10. The shaped electrical conductor of claim 1 wherein the first thickness and the second thickness are different.
 11. The shaped electrical conductor of claim 1 further including: a third sheet of metal having a third thickness; a fifth thermoplastic adhesive pattern on a first surface of the third sheet; a sixth thermoplastic adhesive pattern on a second surface of the third sheet, the sixth pattern being fully justified with the applied fifth pattern; wherein the third sheet is etched to remove metal not covered by the thermoplastic adhesive patterns so that no metal bridges remain between disconnected coated portions of the third sheet; a third contact region in the fourth adhesive pattern bonded to a fourth contact region in the fifth adhesive pattern; and wherein the second and third sheets are mated so that the third contact region is in electrical contact with the fourth contact region.
 12. The shaped electrical conductor of claim 11 wherein the fifth thermoplastic pattern is a rotation of the first thermoplastic pattern.
 13. The shaped electrical conductor of claim 1 wherein the shaped electrical conductor forms a winding pattern for an electric motor.
 14. The shaped electrical conductor of claim 1, wherein the first and second patterns, or the third and fourth patterns, define balancing features in the metal.
 15. The shaped electrical conductor of claim 14, wherein at least one of the balancing features is frangible, so that the frangible balancing feature can be separated from the corresponding metal sheet to provide balance adjustments to improve dynamic or static balance.
 16. The shaped electrical conductor of claim 15, further including punching or stamping the metal sheet corresponding to the frangible balancing feature to define a break line along which the frangible balancing feature can be separated from the corresponding metal sheet.
 17. The shaped electrical conductor according to claim 1, wherein the first and second patterns, or the third and fourth patterns, define an unbalanced feature in the metal not removed from the corresponding metal sheet by the corresponding etching step. 